Currency Exchanges & Transfers

[reddavis]

Generic classes to handle transfers

• We don't want to be tightly integrated with SS as in the near future we may find a better solution or build out own.
• Support exchanges (BTC to ETH) and direct (ETH to ETH) transfers
• [x] Done

Determining If Which Transferable Transfers are Permitted

We need a more explicit way for determining what transfers are permitted. A Transferable object could support being the recipient but not being the source.

An example of this is any GDAX account. GDAX supports withdrawing funds so it can be a source however it does not have an API for getting the accounts address so it is unable to be the recipient.

To add another layer on top...ShapeShift supports setting a return address when sending money. We would only be able to set the return address for those source objects that give us access to their address.

Variables that can determine outcome.

• Withdrawing API: source
• Getting Account Address: recipient
• [x] Done

Extended Permissions

Balance generally* only asks for read permission. To support transfers, Balance would require more permissions for each account taking part in the transfer.

The permissions required for the institutions we currently support are:

• Coinbase
  • wallet:addresses:create
  • wallet:withdrawals:create
• GDAX
  • Transfer + Disable 2 factor auth **
• Poloniex
  • withdrawal privilege must be enabled for your API key

* I say "generally" because for Institutions like GDAX and Poloniex, the user creates a key for Balance, so therefore can select more permissions than Balance really needs.

** We also need to decide whether requesting that 2fa is disabled for Balance transfer API calls is acceptable for the user

• [ ] Improve error handling in the GDAX API client to correctly report issues with permissions and information about what permissions are required

Coinbase Withdraw API

Balance's Coinbase accounts do not currently support the ability to withdraw. This needs to be possible for them to take part in transfers. CB has API's for this: https://developers.coinbase.com/api/v2#withdrawals

• [ ] Done

Poloniex Fetch Account Address API

In order to transfer to a Poloniex account, we need to get the crypto address. Poloniex has API's for this: https://poloniex.com/support/api/.

• [ ] Done

Coinbase Fetch Account Address API

In order to transfer to a CB account, we need to get the crypto address. CB has API's for this: https://developers.coinbase.com/api/v2#addresses.

• Do we create a new address for each transfer? CB seems to create a new addresses every so often.
• [ ] Handle permissions
• [x] Create address with CB API
• [ ] Done

UI

The final version of this is TBD but currently building boilerplate UI and building it into the Balance flow.

• [x] Present/dismiss the transfer view controller
• [x] Display transfer rates and fees
• [x] Let user select source and recipient accounts
• [ ] Error presentation
• [ ] Help UI
• [ ] Done

[ricburton]

This is fantastic @reddavis. I wonder if we could use the popup from Balance Original to highlight the request for new permissions.

[reddavis]

Nice! Yer something like that would be perfect. For some institutions, like GDAX, we may need to provide a walkthrough or something updating permissions is a bit more involved than just clicking a button to reauth.